Process and apparatus for coating wire



Sept. 23 1924. 1,509.101

A. s. DANA PROCESS AND APPARATUS FOR COATING WIRE Filed Jan. 26 1920 INVENTOR all M 1 M BY W M A TTORNEY Patented Sept. 23, 1924.

UNITED STATES ALAN STANDISH DANA, OF SEYMOUR, CONNECTICUT, ASSIGNOB INSULATED WIRE AND CABLE COMPANY, A CORPORATION OF PATENT OFFICE.

TO THE KEBITE CONNECTICUT.

PROCESS AND APPARATUS FOR COATING WIRE.

Application flied January 26, 1920. Serial No. 354,088.

1 '0 all whom it may concern:

Be it known that I, ALAN STANDISH DANA, citizen of the United States, and resident of Seymour, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Processes and Apparatus for Coating Wire, of which the following is a specification.

My invention relates to improvements in process and apparatus for coating wire and more particularly electric conducting wires. My invention is especially adapted for the coating of copper conducting wire with a protecting covering, especially a coherent and adherent coating of lead over which an insulation covering may or may not be apr plied.

For many years it has been understood that copper and the usual rubber insulation should not be placed in intimate contact, and it has been common to first cover the copper wire with tin. Tin has the advantage that it requires only a moderate heat to melt it so that it is fairly easily applied by dipping copper wire into a molten bath of the tin. Tin also readily alloys with copper so that at the temperature of molten tin a firmly adherent coating is gested that wire be coated with lead by dipping the wire in molten lead, but tests indicate that in such case a lead tube is formed which flakes or pulls off the wire very readily. For many years, therefore, the tin coating has been substantially the only covering commercially employed for the purposes in 7 question.

Conductors of this kind are likely to be subjected to hard uses and to all sorts of atmospheric and climatic conditions. In some cases acid or other chemicals are present either in liquid or gaseous form. While the tin coating has heretofore been commonly employed, it is found that under some conditions, after a greater or less of time, the tin coating is destroyed, the inner surface of the insulation is deteriorated, the adhesion of the insulation to the conductor is lost and the surface of the copper is sometimes pitted. The immediate causes of this do not seem to be easily understood and therefore, no method of overcoming these difiiculties have been patent. It may obtained. It has been sug be that the tin under certain conditions gradually becomes wholly alloyed with the copper causing a disappearance of the tin layer and subjecting the insulation to the deteriorating action of the alloy. Probably in some cases electrolysis between the tin, copper and their alloys plays an important part. In some cases alternate wet and dry conditions with or without the presence of acid seem to have something The wide variation in the thickness of tin coating as well as in the thickness of the alloy may possibly accelerate action by electrolysis.

According to my ferred form, I pass invention in its prethe wire continuously through an electrolytic bath depositing thereon a metal coating which is coherent and adherent to the copper whereby the wire is coated in a much more eflicient and satisfactory manner and by using 1 as the metal electro-deposited on the wire I form coating which does not alloy with the copper and is extremely resistant to acids. Also according to my invention the coated conductor may be produced at relatively low cost. Furthermore according to my invention in its preferred form I am able to clean and coat the wire successively in one continuous operation and also ifdesired apply to the lead coated wire suitable insulation material. I have provided an improved form of apparatus for this purpose where by the wire be continuously passed through various parts thereof and from one part to another continuously so thatan msulated electrical conductor provided with the electro-deposited lead coating may be prepared in a most simple and economical manner.

Further ob'ects, features and advanta es will more clearly appear from the etail description given below taken in connection with the accompanying sheet of drawings which form a part of this specification. In the drawin Fig. 1 is a diagram illustrating part 0 an apparatus for provements, the same being 5 own largely in section. Fig. 2 is showing the rest of the paratusthrough which the wire passes. Referring to the drawings 1 represents tion any suitable, electro a reel of copper wire to be treated. The wire from the reel passes over a roller 2 and down into an electrolytic bath 3 in a tank 4. The wire 5 passes around a pulley 6 at the bottom of the tank and then upwardly out of the tank and around a pulley or roller 7 The electrolytic bath 3 com rises a solution of caustic potash. This so ution I make by dissolving 300 grams of dry stick caustic in a similar amount of water and diluting the same in one liter. Preferably several gallons of such a solution are used. 8 re resents an iron or other metal electrode w ich is connected as by wire 9 to the negative side of the battery or other suitable source 10 of electric current. The wire 5 in a bath 3 is made the anode in a manner more fully hereinafter described so that current passes from the wire 5 in the bath 3 to the cathode 8. \Vherc the wire 5 passes into and out of the bath 3 at the surface thereof it is surrounded by small glass tubes 11 so that dirt and the like on the surface of the bath will not be drawn to the wire by reason of the surface tension as the wire passes from the surface, particularlymn its exit from the bath. By passing the wire through this electrolytic ath the wire is cleaned thoroughly. If necessary the bath 3 may be heated and agitated in any suitable manner. However, according to the broader aspects of the invention any other suitable means may be used for cleaning the wire as for example, by pickling or sand blast and in some cases cleaning may not be necessary.

From the caustic cleaning bath the wire 5 after passing around the roller 7 passes around a. roller 12 and down around the rollers 13 in a tank 14 filled with running water in order to remove any caustic or other matters adhering to the wire. Similar glass tubes 15 may be provided where the wire enters and leaves this water bath. he water is continuously run through the tank 14, the same bein admitted throu h the inlet 16 and over owing through t e outlet 17.

After leaving the water bath, the wire 5 passes over rollers 18 and 19 and down around rollers 20 in a tank 22 containing electrolytic bath 23 for depositing upon the wire as it passes therethrough a coherent lead coating firmly adherent to the copper.

ile in the broader as ects of the invenytic bath may be used according to the kind and nature of the metallic coating to be applied, I prefer to use a bath containing lead fluoborate. Such a bath may be prepared by taking 320 ounces of 50% hydrofluoric acid and putting the same into a lead lined tank and slowly adding 140 ounces of. boric acid. After the solution has cooled, 190 ounces of basic lead carbonate are added with continuous stirring. The lead carbonate is added in the form of a cream, pre ared by mixing it with a sli ht amount 0 water. The whole is then difiited to tengallons and ti]- tered through a filter to remove any lead sulphate formed by reason of any sulphuric acid in the hydrofluoric acid as impurity. Before the electrolysis is commenced 100 grams of glue or gelatin are added and stirred in.

In this electrolytic bath the wire is made the cathode and a lead late or plates 24 are provided for an anod ia, these plates being connected by conductor 25 to the positive side of the source 10 through a suitable rheostat 26. Itwill be seen from the above that the current passes from the positive side of the source 10 through the variable resistance 26 to the lead plate anode 24, thence through the bath 23 to the wire 5 in the bath as cathode, thence along the wire 5 into the bath 3 and from the wire in the bath 3 as anode to the cathode 8 and back to the negative side of the source 10. The voltage I prefer to use will vary with the shape of the distance between electrodes and is generally below one volt in the electrodepositing bath. I may use a current density of from 65 to 260 amperes er square foot but over 100 is preferred. he wire 5 is continuously drawn throu h the baths 3, 14 and 23 as will more clear y appear hereinafter and as it moves continuously through the bath 23 I have found that not over seconds is required between the entering of the wire and its exit from the bath in order to de osit thereon a satisfactory lead coating. his lead coating is dense, continuous, coherent and adherent to the copper and of substantially uniform thickness and is substantiall pure and impervious and of substantia ly'the density and homogenity of cast lead and different from lead coverings produced by various other methods wherein the lead is left more or less porous, flaky or non-adherent so that it would not remain impervious. However, many other electrolytes duce a more or less satisfactory coating such for example, as the acetate and silicate electrolytes and indeed the lead or other metal coating may be electro-de osited by any method which roduces a su stantially coherent coating adherent tothe wire conductor. Glass tubes 27 me be provided where the wire 5 enters and leaves the bath 23. Also the bath may be provided with a small agitator on a spindle 46 driven through a suitable pulley 47 so that the bath may be very gently agitated and the li uid kept in motion.

From the bath 23 the wire passes CV81 rollers 28 and 29 and down around rollers 30 and 31 in a bath of runnin water 32 in tank 33, the water being admitted through may be used to prothe pipe 34 and overflowing through pipe 35. In this bath the electrol te which may remain on the wire when it eaves the bath 23 is washed from the wire and then the wire passes out of the bath 32 and around a roller 36 and through a cylinder 37 through which hot air is passed in order to dry off any water that may remain on the surface of the coated wire. Any other suitable means may be used for drying the wire and in some cases drying may not be necessary. If desired the wire 5 may then be drawn between suitable polishing means such as rolls 38 and then through sets of horizontal and vertical stra ghtening rollers 39 and 40. \Vhere there are no kinks or the wire does not need straightening, the straightening rollers.39 and 40 may be omitted. Also under some conditions the polishing rollers 38 may be omitted. After leaving the straightening rollers 39 and 40 the wire is shown as passing around a tractlve drum 41, the wire being given a few turns around the drum 41 which, driven by any suitable means, may serve to continuously pull the wire through the various pieces of apparatus whereby the wire is treated consecutively and continuously by the various steps as above explained. From the tractive drum 41 the wire 5 may be passed through any suitable apparatus 42 for applyin thereto a rubber compound insulation or ot ier form of insulation or protective covering. After passing through the insulation applying means 42 the wire 5 passes over a guide 43 and is wound up upon a take-up reel 44 driven in any suitable manner. The wire may then be placed in iron cylinders and subjected to heat to vulcanize the rubber in a manner well understood by those skilled in the art. For some purposes other forms of insulation may be preferred and in some cases, none at all according to the use of which the conducting wire is to be put. \Vhile my improvements are particularly advantageous in connection with the making of insulated copper wire nevertheless, the lead coating has certain advantages as a protecting coating for wire conductors where no such insulation is used particularly in that .it is resistant to sulphuric and other acids and for th s and other reasons it will be found advantageous as a coating for bronze, iron and other electrical conducting wires, particularly where subjected to severe weather conditions, with or without the insulating covering.

I have pointed out that certain changes and omissions may be made. Other omissions and many ot ier changes and modifica-.

tions may be made without departing from 100 amperes per square foot of cathode area.

the spirit and scope of the invention in its broader aspects. Thus while I have described my improvements in great detail and in connection with a preferred form of apparatus, I do not desireto be limited to the details of the method described nor to the particular apparatus shown, but desire to include all forms coming within the spirit of any one or more of the appended claims.

WVhat I claim and desire to secure by Letters Patent is:

1. The process of coating wire which cons'sts in drawing the wire continuously through a caustic alkali cleanin bath and thereafter without stopping, t irough an electrolytic bath depositing a lead coating on the wire.

2. The process of coating wire which consists in drawing the wire continuously through an electrolytic cleaning bath containing caustic alkali electrolyte and thereafter without stopping, through an electrolytic bath depositing a lead coating on the wire.

3. The process of coating wire which consists in drawing the wire continuously through an electrolytic cleaning bath containing caustic alkali electrolyte and in which the wire forms theanode, and thereafter w'thout stopping, through an electrolytic bath depositmg a lead coating on the wire.

4. The process of coating an electric conducting wire which consists in drawing the wire continuously through an electrolytic bath containing a lead salt electrolyte deposit ng on the wire as it passes through the bath a dense and coherent coating of lead of substantially uniform thickness the current density being over 100 amperes per square foot of cathode area.

5. The process of making insulated wire which includes drawing the wire continuously through an electrolytic bath depositing a lead coating on the wire and, thereafter without stopping, through insulating means applying a rubber compound insulating covering to the lead coated wire.

6. The process of coating copper conducting wire which includes drawing the wire continuously through a chemical cleaning bath, then without stopping, through a washing bath to wash the wire substantially free of chemicals from the wire cleaning bath, and then without stopping, through an electrolytic bath depositing a dense, coherent lead coating on the wire.

7. The process of coating copper electrical conducting wire which consists in drawing the wire continuously through an electrolytic bath of lead fluoborate depositing on the wire as it passes through the bath a coherent and substantially impervious coating of lead the current density being over 8. Apparatus for coating wire having in combination a cleaning bath, a washing bath, and a lead salt electrolytic bath for depositing a lead coating on the wire and means for simultaneously and continuously drawing the wire through the cleaning bath, the washing bath and the electrolytic bath.

9. The process of coating wire which consists in drawing the wire continuously first through an electrolytic cleaning hath, thereafter without stopping the wire through an electrolytic bath depositing a coating of metal on the wire, and thereafter without stopping the wire through means applying an insulating covering to the wire.

10. Apparatus for coating wire having in combination a cleaning bath, a washing bath, a lead salt electrolytic bath depositing a lead coating on the wire, means for appl ing an insulating covering to the wire, and means for simultaneously drawing the wire through the cleaning bath, the washing bath, the electrolytic bathand the insulating means.

11. Apparatus for coating wire having in combination an electrolytic cleaning bath for the wire, an electrolytic bath for depositing a lead coatin on the wire, means for straightening t e wire, means for applying an insulating covering to the wire, and means for drawing the wire continuously and simultaneously through the cleaning bath, lead depositing bath, straightening means and insulatin means. g

12. pparatus for coating wire having in combination means .for cleaning the wire, a lead salt electrolytic bath for depositing a lead coating on the wire, means for straightening the wire, means for applying an insulatin coating to the lead coated wire, and means or simultaneously drawing the wire through the insulatin means, straightening means, electrolytic bat and cleaning means.

13. Ap aratus for coating wire having in combination a lead salt electrolytic bath for depositing a lead coating on the wire, means for straightening the wire, means for applyin an insulating coating to the lead coate wire, and means for simultaneously drawing the wire through the insulating {)neins, straightening means and. electrolytic at i 14. Apparatus for coatin wire having in combination an electrolytic ath for cleaning the wire, an electrolytic bath for depositing a metal coating -on the wire, a source of current, and connections whereby the current from said source asses serially through said cleaning bath and electrolytic bath.

15. The process of treating wire which consists in drawing the wire continuously through an alkaline electrolytic bath to clean the Wire in which the wire forms the anode.

16. The method of cleaning copper conducting wire which consists in drawing the wire gradually through an electrolytic bath of caustic alkali to clean the wire, in which the wire forms the anode.

Signed at New York in the county of New York and State of N day of January, A. D. 1920.

ALAN STANDISH DANA.

ew York, this 23rd a5 Certifi of Correction.

It is hereh certified that in Letterslatent No. 1,509,101, granted. September 23, 1924, upon e application of Alan Standish Dana, of Seymour, Connecticut, for an in rovement in Processes and Ap u-atus for Conti Wire an'error upon an the printed specification requirm correction as in Iowa: Page 2, line 7*,

' more the word glue insert the word agm'd; and that the said Letters Patent should be read with this correction therein that the same may conform to the ree'ord of the case in the Potent Ofliee. f Signed and sealed this th'day of November, 'A. D. 1924.

' [sun] KARL FENNDIG,

Aamfl'mamw of Patents. 

